Metallic-stair construction



Feb. 12, 1929.

R. M. BECHTEL METALLIC STAIR CONSTRUCTION Original Filed July 29', 1925 f5 jza-z-eri' (163.3224 J Patented Feb. 12, 1929.

nonnnr M. BECHTEL, or PHILADELPHIA, PENNSYLVANIA, ASSIGDlOE, BY :nnsnn ASSIGNMENTS, TO' JAMES T. HADLEY, BERWYN, PENNSYLVANIA.

METALLIC-STAIR consrnucrron.

Refiie for abandoned application serial No. 46,778, filed nay-2a, 1925.

This application filed June 22,

1928. K Serial No. 287,377.

lily invention relates to new and useful in'iprovements in a metallic stair construction, and more particularly to the manner of installing or method of fastening the several parts together in order to provide a strong and rigid structure.

The primary object of the invention'is to,

provide an L-shaped bolt for fastening adjacent parts of two stair units to a stringer thereby eliminating the use of angle iron supports and effecting a considerable saving in the cost of labor for erection ofthe stairway.

Another object of the invention is to provide an exceedingly simple and effective fastening means which will be light in weight although strong and durable and when in place will effectually hold three elements in position without undue strain on the fastening means.

A still further object of the invention is to provide a stair unit having apertures, preferably elliptical, adjacent each end and near the front of the primary tread and also having holes near the ends of the flange at or adjacent the upper end of the riser.

The invention herein referred to comprises parallel stringers having lower inturned flanges and preferably upper outturned flanges and between these stringers are mounted several co-operating units each including .a stair tread and riser, the latter being provided. with a flange, of any desirable shape, design or configuration and these units are so placed that the lower portions of the risers rest upon. the lower inturned flanges of the stringers Where they are secured by suitable fastening means, such as bolts, so that the weight of the next succeeding stair tread is supported by the riser While the weight of the stair tread formed with a riser in one unit is supported by the riser of the preceding unit. The stair tread of one unit and the riser of another unit, through the medium of its flange, are rigidly held to the stringers by the L-shaped bolts.

With these ends in view, this invention consists in the details of construction and combination of elements hereinafter set forth and then specifically designated by the claim.

In order that those skilled in the art to which this invention appertains may understand how to use and make the same, I will describe its constructionindetail, referring by numerals to the accompanying drawing forming a part of this application, in which i Fig. 1, is a plan view ofa portion of a metallic stair construction embodying my invention. 1

2, is aside elevation thereof with a part of the nearside stringer broken away to illustrate details of construction. i

"Fig. 3, isa' perspective view ofone'form of unit herein used to illustrate the manner of carrying out'the invention.

F i, is an enlarged vertical sectional view through a tread, the flange of a riser and a stringer detailing the joint between the parts.

In carrying out my invention as herein embodied, 5 represents the stringers, each having'a lower inturncd flange 6 and preferably an upper outturned flange '7, although the latter is not absolutely essential and under some conditions may be eliminated. Between the stringers are mounted the several units 8 which cooperate to produce the stairs and these units each include a tread 9, a riser 10, and a flange 11. These are the essential elements of the unit whether they be formed integral or separately and secured to each other and regardless of their pan ticular arrangement for producing different designs orconfigurations. The tread 9 has apertures 12,preferably of elliptical shape formed therein a suitable distance from each end near the front thereof as plainly shown in Fig. 3, while the flange 11 of the riser has holes 13 passing therethrough at substantially the same distance from the ends of said flange as the outer ends of the apertures '12 in order that the holes 13 in the flange of one unit will align with the outer ends of the apertures 12 of a. co-acting or succeeding unit when the parts are installed.

When the stair units are properly positionedth-e lower ends of the risers rest upon the lower inturned flanges 6 of the stringers and are there fastened by suitable fastening devicesll, such bolts and nuts, the bolts passing through the stringer flanges and through holes at the lower ends of the risers. he forward ends of the treads rest upon the flanges 11 of the riser of the succeeding unit so that-the weight ofthe stairs, and more particularly the stair treads, is supported by the stringer flanges through the medium of the risers.

In order to firmly and rigidly hold the parts together. L-shaped bolts 16 are provided which coact with the treads, riser flanges and stringers. One leg of each bolt passes through a hole 17 in the web of a stringer above a stair tread while the other leg of said bolt passes through an aperture in said stair tread and through a hole 13 in the co acting riser flange and on the legs of the bolt are threaded the nuts 18, 19 for drawing the parts into place and firmly securing the same.

Of course I do not wish to be limited to the exact details of construction as herein shown, as these may be varied within the limits of the appended claim without departing from the spirit of my invention.

Having thus fully described my invention, what I claim as new and useful is A metallic stair construction including a pair of parallel stringers, inturned flanges along the lower edges of said stringers, stair units, each comprising a tread, a riser, and

a flange projecting from the upper end of i said riser, said units being mounted between the stringers withthe lower ends of the risers resting on the riser flanges or the preceding units, said treads having elongated apertures adjacent their ends and near the front thereof and said riser flanges having holes adjacent their ends for alignment with the outer ends of the apertures in a co-acting tread, L-bolts each having horizontal legs passing through the stringers above the respective treads and vertical legs passing through the apertures in the treads and the holes in the riser flanges, and nuts having threaded connection with the legs of the bolts, whereby the riser of a preceeding stair, through its flange, is adjusted laterally relative to the tread of a succeeding stair. I

In testimony whereof, I have hereunto affixed my signature.

ROBERT M. BEOHTEL 

